A year ago, an article by Joseph Dietzgen titled "Marxism and the Latest Revolution in Natural Science" (1906–1907, no. 52) appeared in the journal *Die Neue Zeit*. The deficiency of this article lies in its ignoring the epistemological conclusions that are drawn from the "new" physics and which are of particular interest to us at the present time. But this very deficiency makes the viewpoint and conclusions of the aforementioned author especially interesting to us. Joseph Dietzgen stands, like the author of these lines, on the standpoint of that very same "rank-and-file Marxist" of whom our Machists speak with such magnificent contempt. "A dialectical materialist," writes, for example, Mr. Yushkevich, "is what an ordinary, rank-and-file Marxist usually calls himself" (p. 1 of his book). This very rank-and-file Marxist in the person of J. Dietzgen directly compared the latest discoveries in natural science, and especially in physics (X-rays, Becquerel rays, radium{73} and so forth), with Engels' *Anti-Dühring*. What conclusion did this comparison lead him to? "In the most varied domains of natural science," writes J. Dietzgen, "new knowledge has been acquired, and all of it reduces to the point that Engels wanted to bring to the fore, namely to the fact that in nature 'there are no irreconcilable opposites, no violently fixed demarcation lines and differences' and that, if opposites and differences are encountered in nature, then their immobility, their absoluteness are introduced into nature exclusively by us." They discovered, for example, that light and electricity are merely manifestations of one and the same force of nature{74}. With each passing day it becomes more probable that chemical affinity reduces to electrical processes. The indestructible and decomposable elements of chemistry, whose number continues to grow as if in mockery of the unity of the world, turn out to be destructible and decomposable. The element radium has been transformed into the element helium{75}. "Just as all forces of nature reduce to one force, so all substances of nature reduce to one substance" (italics of J. Dietzgen). Having cited the opinion of one of the writers who considers the atom merely a condensation of ether{76}, the author exclaims: "How brilliantly Engels' pronouncement is confirmed: motion is the form of existence of matter." "All phenomena of nature are motion, and the difference between them consists only in the fact that we, human beings, perceive this motion in different forms… The matter stands precisely as Engels said. Just like history, nature is subject to the dialectical law of motion."

On the other hand, one cannot take up the literature of Machism or literature about Machism without encountering pretentious references to the new physics which, supposedly, refuted materialism and so on and so forth. Whether these references are well-founded is another question, but the connection between the new physics or, more precisely, a certain school in the new physics and Machism and other varieties of contemporary idealist philosophy admits of not the slightest doubt. To examine Machism while ignoring this connection – as Plekhanov does{77} – means to make sport of the spirit of dialectical materialism, that is, to sacrifice Engels' method for one or another of Engels' formulations. Engels says directly that "with every discovery that constitutes an epoch, even in the natural-historical sphere" (not to mention the history of mankind) "materialism is inevitably obliged to change its form" (*L. Feuerbach*, p. 19, German edition){78}. Consequently, a revision of the "form" of Engels' materialism, a revision of his natural-philosophical propositions contains in itself nothing "revisionist" in the established sense of the word; on the contrary, it is demanded as necessary by Marxism. We reproach the Machists not at all for such a reconsideration, but for their purely revisionist procedure – of altering the essence of materialism under the guise of criticism of its form, of adopting the basic propositions of reactionary bourgeois philosophy without any attempt to deal directly, openly and decisively with such assertions as Engels', which are absolutely extremely essential in this question, such as his assertion: "…motion is unthinkable without matter" (*Anti-Dühring*, p. 50){79}.

It goes without saying that, in examining the question of the connection of one school of the latest physicists with the revival of philosophical idealism, we are far from any intention of touching upon the special teachings of physics. We are interested exclusively in the epistemological conclusions drawn from certain definite positions and well-known discoveries. These epistemological conclusions force themselves upon us so much that they are already raised by many physicists. Moreover, among physicists there are already various tendencies; definite schools are formed on this basis. Our task, therefore, is limited to presenting clearly wherein lies the essence of the divergence of these tendencies and in what relation they stand to the basic lines of philosophy.

## 1. The Crisis of Contemporary Physics

The well-known French physicist Henri Poincaré says in his book on *The Value of Science* that there are "signs of a serious crisis" in physics, and devotes a special chapter to this crisis (ch. VIII, cf. p. 171). This crisis is not limited to the fact that "the great revolutionary – radium" undermines the principle of conservation of energy. "All other principles are also endangered" (180). For example, the principle of Lavoisier, or the principle of conservation of mass, turns out to be undermined by the electronic theory of matter. According to this theory, atoms form the smallest particles, charged with positive or negative electricity, called electrons and "immersed in a medium which we call the ether." The experiments of physicists provide material for calculating the velocity of the motion of electrons and their mass (or the ratio of their mass to their electrical charge). The velocity of motion turns out to be comparable to the velocity of light (300,000 kilometers per second), for example, reaching a third of this velocity. Under such conditions, one must take into account a twofold mass of the electron corresponding to the necessity of overcoming the inertia, first, of the electron itself and, second, of the ether. The first mass will be the real or mechanical mass of the electron; the second – the "electrodynamic mass, representing the inertia of the ether." And so, the first mass turns out to be equal to zero. The entire mass of electrons, or, at least, of negative electrons, turns out to be in its origin wholly and exclusively electrodynamic. Mass disappears. The foundations of mechanics are undermined. Newton's principle is undermined, the equality of action and reaction, and so on.{80}

Before us, says Poincaré, are the "ruins" of the old principles of physics, a "universal collapse of principles." True, he stipulates, all the indicated exceptions from principles relate to infinitesimally small magnitudes – it is possible that other infinitesimally small magnitudes, which would counteract the undermining of the old laws, we do not yet know – and radium is moreover very rare, but in any case "a period of doubt" is present. The epistemological conclusions of the author from this "period of doubt" we have already seen: "nature does not give us (or impose upon us) the concepts of space and time, but we give them to nature"; "all that is not thought is pure nothingness." These are idealist conclusions. The breaking up of the most fundamental principles proves (such is Poincaré's line of thought) that these principles are not some kind of copies, imprints taken from nature, not images of something external in relation to human consciousness, but products of that consciousness. Poincaré does not develop these conclusions consistently, nor is he interested in any significant way in the philosophical side of the question. The French writer on philosophical questions Abel Rey examines it in great detail in his book: *The Theory of Physics in Contemporary Physicists* (*Abel Rey: "La théorie de la physique chez les physiciens contemporains", Paris, F. Alcan, 1907*). True, the author is himself a positivist, that is, a muddler and half a Machist, but in this case even that presents a certain advantage, since one cannot suspect him of desiring to "slander" the idol of our Machists. One cannot trust Rey when it comes to precise philosophical definition of concepts and to materialism in particular, since Rey too is a professor and, as such, is full of infinite contempt for materialists (and distinguished by infinite ignorance regarding the epistemology of materialism). Needless to say, such figures as Marx or Engels simply do not exist for such "men of science." But Rey carefully and on the whole conscientiously reviews the extremely rich literature on the question, not only French, but also English and German (Ostwald and Mach especially), so that we will frequently make use of his work.

The attention of philosophers in general, says the author, and also of those who, for motives of one kind or another, wish to criticize science in general, is now attracted especially to physics. "In discussing the limits and value of physical knowledge, one essentially criticizes the legitimacy of positive science, the possibility of knowledge of the object" (p. I–II). From the "crisis of contemporary physics" people hasten to draw skeptical conclusions (p. 14). What, then, is the essence of this crisis? During the first two-thirds of the nineteenth century, physicists were in agreement on all essentials. "They believed in a purely mechanical explanation of nature; they assumed that physics was merely a more complex mechanics, namely molecular mechanics. They differed only on the question of the procedures for reducing physics to mechanics, on the details of the mechanism." "At present the spectacle presented to us by the physico-chemical sciences seems completely contrary. Extreme disagreements have replaced the former unanimity, and moreover disagreements not in details, but in fundamental and guiding ideas. While it would perhaps be an exaggeration to say that each scientist has his own special tendencies, it is nevertheless necessary to state that, like art, science, especially physics, has numerous schools, whose conclusions often diverge, and sometimes are directly hostile to one another…

"From this one can see what significance and what breadth belongs to that which has received the name of the crisis of contemporary physics.

"Traditional physics until the middle of the nineteenth century assumed that it would suffice simply to continue physics in order to obtain the metaphysics of matter. This physics attributed ontological significance to its theories. And these theories were wholly mechanical. Traditional mechanism" (Rey uses this word in the special sense of a system of views reducing physics to mechanics) "represented in this way, beyond the results of experience, at the limits of the results of experience, real knowledge of the material world. This was not hypothetical expression of experience – this was dogma" (16)…

Here we must interrupt the esteemed "positivist." It is clear that he is depicting to us the materialist philosophy of traditional physics, unwilling to call the devil (that is, materialism) by name. To a Humist, materialism must seem metaphysics, dogma, a going beyond the limits of experience and so on. Not knowing materialism, Humist Rey has no conception whatsoever of dialectics, of the distinction between dialectical materialism and metaphysical materialism in Engels' sense of the word. Therefore, for example, the relation of absolute and relative truth is absolutely obscure to Rey.

"…Critical remarks against traditional mechanism, which were made in the second half of the nineteenth century, undermined this presupposition of the ontological reality of mechanism. On this criticism was founded the philosophical view of physics which became already almost traditional in the philosophy of the end of the nineteenth century. Science, according to this view, is nothing more than a symbolic formula, procedures of marking (designation, *repérage*, creation of signs, marks, symbols), and since these marking procedures are different in different schools, it was soon concluded that only that which was previously created (*façonné*) by man for designation (for symbolization) is marked thereby. Science became a work of art for dilettantes, a work of art for utilitarians: points of view which naturally began everywhere to be interpreted as a denial of the possibility of science. Science, as a purely artificial means of acting upon nature, as a mere utilitarian technique, has no right to be called science if the meaning of words is not to be distorted. To say that science can be nothing other than such an artificial means of acting is to deny science in the true sense of the word.

"The collapse of traditional mechanism, or rather, that criticism to which it was subjected, led to the following: science too suffered a collapse. From the impossibility of holding simply and exclusively to traditional mechanism, it was concluded that science is impossible" (16–17).

And the author poses the question: "Does the contemporary crisis of physics represent a temporary and external incident in the development of science, or is science suddenly turning backwards and finally abandoning the path on which it has been traveling?…"

"…If the physico-chemical sciences, which in history have essentially been champions of emancipation, suffer a collapse in such a crisis which leaves for them exclusively the value of technically useful recipes but deprives them of all significance from the point of view of knowledge of nature, then from this there must ensue a complete overthrow in both logic and the history of ideas. Physics loses all educational value; the spirit of positive science represented by it becomes false and dangerous." Science can give only practical recipes, not true knowledge. "The knowledge of reality must be sought by other means… One must go another way; one must restore to subjective intuition, mystical feeling of reality, in a word, to the mysterious, that which was considered taken away from them by science" (19).

As a positivist, the author considers such a view incorrect and the crisis of physics temporary. How Rey cleanses Mach, Poincaré and Company of these conclusions we shall see below. For now we shall limit ourselves to establishing the fact of the "crisis" and its significance. From Rey's last words quoted by us, it is clear what reactionary elements took advantage of this crisis and exacerbated it. In the preface to his work Rey says directly that the "general spirit of contemporary physics" is sought to be relied upon by the "fideistic and anti-intellectualist movement of the last years of the nineteenth century" (II). Fideists (from the Latin word *fides*, faith) are called in France those who place faith above reason. Anti-intellectualism is called the doctrine denying the rights or pretensions of reason. Consequently, philosophically speaking, the essence of the "crisis of contemporary physics" consists in the fact that the old physics saw in its theories "true knowledge of the material world," that is, reflection of objective reality. The new current in physics sees in theory only symbols, signs, marks for practice, that is, it denies the existence of objective reality independent of our consciousness and reflected by it. If Rey adhered to correct philosophical terminology, he should have said: the materialist theory of knowledge, which was stichially assumed by earlier physics, has been replaced by an idealist and agnostic one, which fideism made use of, contrary to the wishes of idealists and agnostics.

But this replacement, which constitutes the crisis, Rey does not present as if all new physicists stood against all old physicists. No. He shows that according to their epistemological tendencies contemporary physicists are divided into three schools: the energetic or conceptualist school (*conceptuelle* – from the word concept, pure conception), the mechanist or new-mechanist school, which the vast majority of physicists continues to hold to, and an intermediate school between them, the critical school. To the first belong Mach and Duhem; to the third, Henri Poincaré; to the second, Kirchhoff, Helmholtz, Thomson (Lord Kelvin), Maxwell from the old, Larmor, Lorentz from the newest physicists. The essence of the two basic lines (for the third is not independent but intermediate) is evident from the following words of Rey:

"Traditional mechanism constructed a system of the material world." In the doctrine of the structure of matter, it proceeded from "elements qualitatively homogeneous and identical," and the elements had to be regarded as "unchanging, impenetrable" and so on. Physics "built a real building from real materials and real cement. The physicist possessed material elements, causes and the mode of their action, real laws of their action" (33–38). "The changes in this view of physics consist predominantly in that they discard the ontological value of theories and extremely emphasize the phenomenological significance of physics." The conceptualist view deals with "pure abstractions," "seeks a theory purely abstract, eliminating, as far as possible, the hypothesis of matter." "The concept of energy becomes the substructure of the new physics. Therefore the conceptualist physics can for the most part be called energetic physics," although this designation does not apply, for example, to such a representative of conceptualist physics as Mach (p. 46).

This mixing of energetics with Machism in Rey is, of course, not entirely correct, just as it is also not correct that the new-mechanist school also arrives at the phenomenological view of physics (p. 48), in spite of all the depth of its divergence from the conceptualists. Rey's "new" terminology does not clarify matters but obscures them, but we could not avoid it to give the reader an idea of the "positivist's" view of the crisis of physics. Essentially speaking, the opposition of the "new" school to the old view entirely coincides, as the reader could convince himself, with the above-cited criticism of Helmholtz by Kleinpeter. In transmitting the views of different physicists, Rey reflects in his exposition all the indefiniteness and shakiness of their philosophical views. The essence of the crisis of contemporary physics consists in the breaking of old laws and fundamental principles, in the rejection of objective reality outside consciousness, that is, in the replacement of materialism by idealism and agnosticism. "Matter has disappeared" – thus one can express the basic and typical difficulty, in relation to many particular questions, which created this crisis. We shall dwell on this difficulty.

## 2. "Matter Has Disappeared"

Among contemporary physicists one can find literally such an expression in describing the latest discoveries. For example, L. Ulwig in his book *Evolution of the Sciences* entitled the chapter on the new theories concerning matter: "Does Matter Exist?" "The atom demaeterializes itself," he says there, "matter disappears."[162] To see how easily the Machists make fundamental philosophical conclusions from this, let us take even Valentinov. "The assertion that scientific explanation of the world obtains solid foundation 'only in materialism,'" he writes, "is no more than a fiction – and moreover an absurd fiction" (p. 67). As the destroyer of this absurd fiction, the well-known Italian physicist Augusto Righi is cited, who says that the electronic theory "is not so much a theory of electricity as a theory of matter; the new system simply puts electricity in the place of matter" (*Augusto Righi. "Die moderne Theorie der physikalischen Erscheinungen", Lpz., 1905, S. 131*[163]. There is a Russian translation). After quoting these words (p. 64), Mr. Valentinov exclaims:

"Why does Augusto Righi permit himself to inflict this insult on sacred matter? Perhaps because he is a solipsist, an idealist, a bourgeois critic, a so-called empiriocritist or something even worse than that?"

This remark, which seems to Mr. Valentinov devastatingly virulent against materialists, shows all his virgin innocence in the question of philosophical materialism. Wherein consists the true connection of philosophical idealism with the "disappearance of matter," this Mr. Valentinov absolutely did not understand. And the "disappearance of matter" of which he speaks after contemporary physicists has no relation to the epistemological distinction between materialism and idealism. To clarify this, let us take one of the most consistent and clear Machists, Karl Pearson. The physical world for him is a group of sensory perceptions. "Our cognitive model of the physical world," he illustrates with the following diagram, with the proviso that the ratio of dimensions is not observed by this diagram (p. 282, *The Grammar of Science*):

Simplifying his diagram, K. Pearson completely eliminated the question of the relation of ether and electricity or positive and negative electrons. But this is not important. What is important is that Pearson's idealist viewpoint regards "bodies" as sensory perceptions, and then the composition of these bodies from particles, particles from molecules, and so on, concerns changes in the model of the physical world, and in no way concerns the question of whether bodies are symbols of sensations or sensations are images of bodies. Materialism and idealism are distinguished by one or another solution of the question of the source of our knowledge, of the relation of knowledge (and the "psychical" in general) to the physical world, while the question of the structure of matter, of atoms and electrons, is a question concerning only this "physical world." When physicists say: "matter disappears," they want to say by this that up to now natural science has led all its investigations of the physical world to three ultimate concepts – matter, electricity, ether; now only two remain, since matter succeeds in reducing to electricity,[164] the atom succeeds in explaining as a likeness of an infinitesimally small solar system, within which around a positive electron{81} negative electrons{82} move with a definite (and immensely vast, as we have seen) velocity. Instead of dozens of elements, it succeeds, consequently, in reducing the physical world to two or three (insofar as positive and negative electrons constitute "two essences substantially different," as physicist Pella says – *Rey, l. c., p. 294–295*[165]). Natural science leads, consequently, to the "unity of matter" (ibid.)[166] – there is the true content of the phrase about the disappearance of matter, about the replacement of matter by electricity and so on, which confuses so many. "Matter disappears" – this means the limit to which we have known matter up to now disappears; our knowledge goes deeper; such properties of matter disappear which seemed before to be absolute, unchanging, primary (impenetrability, inertia, mass{83} and so on) and which now are revealed as relative, belonging only to certain states of matter. For the only "property" of matter with which the recognition of philosophical materialism is connected is the property of being objective reality, existing outside our consciousness.

The error of Machism generally and of Machist new physics consists in that this basis of philosophical materialism is ignored and the distinction between metaphysical materialism and dialectical materialism is not observed. Recognition of certain unchanging elements, an "unchanging essence of things" and so forth is not materialism, but metaphysical, that is, anti-dialectical materialism. Therefore J. Dietzgen emphasized that "the object of science is infinite," that it is not only the infinite that is immeasurable, unknowable to the end, inexhaustible, but also the "smallest atom," because "nature in all its parts without beginning and without end" (*Kleinere philosophische Schriften*, S. 229–230[167]). Therefore Engels cited his example of the discovery of alizarin in coal-tar and criticized mechanical materialism. To pose the question from the only correct, that is, dialectical-materialist, point of view, one must ask: do electrons, ether and so forth exist outside human consciousness as objective reality or not? To this question natural scientists will as unhesitatingly answer yes, and do constantly answer, as they without hesitation recognize the existence of nature before man and before organic matter. And by this the question is decided in favor of materialism, for the concept of matter, as we have already said, signifies epistemologically nothing other than objective reality existing independently of human consciousness and reflected by it.

But dialectical materialism insists on the approximate, relative character of every scientific proposition about the structure of matter and its properties, on the absence of absolute boundaries in nature, on the transformation of moving matter from one state to another, which from our point of view appears irreconcilable with it and so on. However strange from the point of view of "common sense" the transformation of weightless ether into weighty matter and vice versa, however "strange" the absence in the electron of any other mass besides the electromagnetic, however unusual the limitation of the mechanical laws of motion to only one domain of natural phenomena and their subordination to deeper laws of electromagnetic phenomena and so on – all this is only further confirmation of dialectical materialism. The new physics lapsed into idealism chiefly precisely because physicists did not know dialectics. They struggled with metaphysical (in Engels' sense, not in the positivist, that is, Humist, sense of the word) materialism, with its one-sided "mechanism" – and in doing so they threw the baby out with the bath water. Denying the unchangeability of the elements and properties of matter that were known up to then, they slid into the denial of matter, that is, objective reality of the physical world. Denying the absolute character of the most important and fundamental laws, they slid into the denial of any objective lawfulness in nature, into declaring the law of nature a mere convention, "limitation of expectation," "logical necessity" and so on. Insisting on the approximate, relative character of our knowledge, they slid into the denial of the object independent of knowledge being reflected approximately correctly, relatively truly by that knowledge. And so on, and so on, without end.

The arguments of Bogdanov in 1899 about the "unchanging essence of things," the arguments of Valentinov and Yushkevich about "substance" and so on – all this is the fruit of ignorance of dialectics. From Engels' point of view, only one thing is unchanging: this is the reflection by human consciousness (when human consciousness exists) of the external world existing independently of it and developing. No other "unchangingness," no other "essence," no "absolute substance" in the sense that idle professorial philosophy has depicted these concepts exists for Marx and Engels. The "essence" of things or "substance" is also relative; it expresses only the deepening of human knowledge of objects, and if yesterday this deepening did not go beyond the atom, today – beyond the electron and ether, then dialectical materialism insists on the temporary, relative, approximate character of all these milestones of knowledge of nature by progressive human science. The electron is as inexhaustible as the atom; nature is infinite, but it infinitely exists, and this – the sole categorical, sole unconditional recognition of its existence outside consciousness and sensation of man – is what distinguishes dialectical materialism from relativist agnosticism and idealism.

Let us cite two examples of how new physics wavers unconsciously and stichially between dialectical materialism, which remains unknown to bourgeois scientists, and "phenomenalism" with its inevitable subjectivist (and subsequently directly fideist) conclusions.

That same Augusto Righi, whom Mr. Valentinov did not know how to question regarding the matter that interested him about materialism, writes in the introduction to his book: "What exactly are electrons or electrical atoms, this remains a mystery even now; but, despite this, the new theory is destined, perhaps, to acquire with time no small philosophical significance, insofar as it arrives at completely new premises regarding the structure of weighty matter and strives to reduce all phenomena of the external world to one common origin.

"From the point of view of the positivist and utilitarian tendencies of our time, such an advantage, perhaps, is not important, and the theory can be recognized first of all as a means of conveniently arranging and comparing facts, as a guide in the search for further phenomena. But if in former times one perhaps related with too much confidence to the capabilities of the human spirit and too easily thought to grasp with one's hands the ultimate causes of all things, then in our time there is a tendency to fall into the opposite error" (l. c., S. 3).

Why does Righi guard himself here against positivist and utilitarian tendencies? Because he, apparently having no definite philosophical standpoint, stichially holds to the reality of the external world and to the recognition of the new theory not merely as a "convenience" (Poincaré), not merely as an "empiriosymbol" (Yushkevich), not merely as "harmonization of experience" (Bogdanov) and whatever else such subjectivist perversions are called, but as a further step in the knowledge of objective reality. If this physicist had become familiar with dialectical materialism, his judgment about the error opposite to the old metaphysical materialism might have become, perhaps, the starting point of correct philosophy. But the entire milieu in which these people live repels them from Marx and Engels, throws them into the embrace of vulgar official philosophy.

Rey too is absolutely unfamiliar with dialectics. But he too is compelled to establish that among the newest physicists there are continuers of the traditions of "mechanism" (that is, materialism). Following the path of "mechanism," Rey says, are not only Kirchhoff, Hertz, Boltzmann, Maxwell, Helmholtz, Lord Kelvin. "Pure mechanists and from a certain point of view more mechanists than anyone else, representing the final word (*l'aboutissant*) of mechanism, are those who, following Lorentz and Larmor, formulate the electrical theory of matter and come to the denial of the constancy of mass, declaring it a function of motion. All of them are mechanists, since they take real motions as their starting point" (italics of Rey, p. 290–291).

"…If the new hypotheses of Lorentz, Larmor and Langevin were confirmed by experiment and acquired a sufficiently firm basis for systematizing physics, it would undoubtedly be the case that the laws of contemporary mechanics depend on the laws of electromagnetism; the laws of mechanics would be a special case and would be strictly limited to definite boundaries. The constancy of mass, our principle of inertia would retain force only for mean velocities of bodies, understanding the term 'mean' in relation to our sensations and to the phenomena constituting our ordinary experience. A general overhaul of mechanics would become necessary, and consequently also a general overhaul of physics as a system.

"Would this mean a rejection of mechanism? Not in the slightest. The purely mechanist tradition would continue to be preserved, mechanism would proceed along the normal path of its development" (295).

"Electron physics, which should be ranked among theories mechanist in general spirit, strives to give its own systematization to all of physics. This physics of electrons, although its basic principles are taken not from mechanics but from experimental data of the theory of electricity, is mechanist in spirit, because 1) it employs elements imagined (*figurés*) as material in order to represent physical properties and their laws; it expresses itself in terms of perception. 2) If it does not regard physical phenomena as special cases of mechanical phenomena, it does regard mechanical phenomena as a special case of physical phenomena. The laws of mechanics remain, consequently, in direct connection with the laws of physics; the concepts of mechanics remain concepts of the same order as the concepts of physico-chemical science. In traditional mechanism these concepts were copied (*calqués*) from comparatively slow motions which, being the only ones known and accessible to direct observation, were adopted… as the types of all possible motions. New experiments showed that it is necessary to expand our conception of possible motions. Traditional mechanics remains entirely intact, but it is applicable now only to comparatively slow motions… With respect to great velocities, the laws of motion turn out to be different. Matter reduces to electrical particles, the ultimate elements of the atom… 3) Motion, displacement in space, remains the only imagined (*figuré*) element of physical theory. 4) Finally – and from the point of view of the general spirit of physics, this consideration stands above all the rest – the view of physics, of its method, of its theories and their relation to experience, remains absolutely identical with the views of mechanism, with the theory of physics from the epoch of the Renaissance" (46–47).

I have cited these lengthy excerpts from Rey in full because it would be impossible to present his assertions otherwise given his constant fear of avoiding "materialist metaphysics." But however much Rey and the physicists about whom he speaks disavow themselves from materialism, it nevertheless remains undoubted that mechanics was a copy of slow real motions, and new physics is a copy of gigantically fast real motions. The recognition of theory as a copy, an approximate image of objective reality – in this consists materialism. When Rey says that among new physicists there is "a reaction against the conceptualist (Machist) and energetic school," and when he ranks the representatives of this reaction among the physicists of electron theory (46), we could not wish for better confirmation of the fact that the struggle is, in essence, between materialist and idealist tendencies. One must not forget, however, that aside from the general prejudices of all cultured philistinism against materialism, the most outstanding theorists are marked by complete unfamiliarity with dialectics.

## 3. Is Motion Thinkable Without Matter?

The use by philosophical idealism of new physics, or the idealist conclusions drawn from it, is caused not by the fact that new types of substance and force are discovered, matter and motion, but by the attempt to think motion without matter. The Machists have simply not examined this very attempt. They did not wish to reckon with Engels' assertion that "motion is unthinkable without matter." J. Dietzgen as far back as 1869, in his *The Essence of Human Mental Work*, expressed the same thought as Engels – true, not without his usual muddled attempts to "reconcile" materialism with idealism. Let us set aside these attempts, explained to a significant extent by the fact that Dietzgen polemicizes with Büchner's materialism, which is alien to dialectics, and look at Dietzgen's own statements on the question of interest to us. "Idealists wish," says Dietzgen, "for the general without the particular, for spirit without matter, for force without substance, for science without experience or without material, for the absolute without the relative" (*Das Wesen der menschlichen Kopfarbeit*, 1903, S. 108[168]). So Dietzgen connects the striving to tear motion from matter, force from substance, with idealism, places it alongside the striving to tear thought from the brain. "Liebig," continues Dietzgen, "who loves to make digressions from his inductive science in the direction of philosophical speculation, says in the sense of idealism: one cannot see forces" (109). "A spiritualist or idealist believes in the spiritual, that is, the spectral, inexplicable being of force" (110). "The opposition between force and substance is as old as the opposition between idealism and materialism" (111). "Of course, there is no force without substance, no substance without force. Substance without force and force without substance is nonsense. If idealist natural scientists believe in the non-material being of forces, then in this point they are not natural scientists but… spiritualist" (114).

We see from this that forty years ago there also appeared natural scientists ready to admit the thinkability of motion without matter, and that Dietzgen declared them "in this point" spiritualists. What, then, is the connection of philosophical idealism with the separation of matter from motion, with the elimination of substance from force? Is it not really "more economical" to think motion without matter?

Let us imagine a consistent idealist who stands, say, on the point of view that the entire world is my sensation or my representation and so forth (if we take "no one's" sensation or representation, this will change only the variety of philosophical idealism, but will not change its essence). An idealist would not even think of denying that the world is motion, namely: the motion of my thoughts, representations, sensations. An idealist will reject the question of what moves and consider it absurd: the change of my sensations, the disappearing and appearing of representations, and that is all. Outside me there is nothing. "Motion" – and that's that. One cannot imagine more "economical" thinking. And by no proofs, syllogisms, definitions can one refute a solipsist if he consistently pursues his viewpoint.

The basic distinction of a materialist from a proponent of idealist philosophy consists in that sensation, perception, representation and in general the consciousness of man are taken as an image of objective reality. The world is the motion of this objective reality reflected by our consciousness. To the motion of representations, perceptions and so on there corresponds the motion of matter outside me. The concept of matter expresses nothing other than objective reality given us in sensation. Therefore to tear motion from matter is equivalent to tearing thought from objective reality, tearing my sensations from the external world, that is, to go over to the side of idealism. The trick usually performed with the negation of matter, with the admission of motion without matter, consists in remaining silent on the relation of matter to thought. The matter is presented as if this relation did not exist, but in reality it is smuggled in, remains unstated at the beginning of the argument, but emerges more or less imperceptibly later.

"Matter has disappeared," we are told, wishing to draw epistemological conclusions from this. But has thought remained? – we ask. If not, if with the disappearance of matter thought has also disappeared, with the disappearance of the brain and nervous system representations and sensations have also disappeared – then everything has disappeared, your argument too has disappeared, as one example of some kind of "thought" (or lack of thought)! But if yes, if with the disappearance of matter thought is presupposed not to have disappeared, then you, that means, have secretly gone over to the point of view of philosophical idealism. This is precisely what always happens with people who, out of "economy," wish to think motion without matter, for tacitly, simply by the fact that they continue their argument, they acknowledge the existence of thought after the disappearance of matter. And this means that very simple or very complex philosophical idealism is taken as the basis: very simple if the matter reduces openly to solipsism (I exist, the entire world is only my sensation); very complex if instead of the thought, representation, sensation of a living man, there is taken a dead abstraction: no one's thought, no one's representation, no one's sensation, thought in general (absolute idea, universal will and so forth), sensation as an indefinite "element," "the psychical," substituted under all physical nature and so on and so forth. Between the varieties of philosophical idealism are possible thousands of shadings, and one can always create the thousand-and-first shading, and to the author of such a thousand-and-first little system (for example, empirimonism) the distinction of it from the rest may seem important. From the point of view of materialism these distinctions are entirely insubstantial. What is substantial is the starting point. What is substantial is that the attempt to think motion without matter smuggles in thought torn from matter, and this is philosophical idealism.

Therefore, for example, the English Machist Karl Pearson, the most clear, consistent, hostile to verbal evasions Machist, directly begins chapter VII of his book, devoted to "matter," with a paragraph bearing the characteristic title: "All things move – but only in conception." "Regarding the domain of perceptions it is idle to ask what moves and why it moves" (p. 243, *The Grammar of Science*[169]).

Therefore too Bogdanov's philosophical misfortunes began actually before his acquaintance with Mach, began from the moment he believed the prominent chemist and petty philosopher Ostwald that one can think motion without matter. It is appropriate to dwell on this long-past episode of Bogdanov's philosophical development all the more since one cannot bypass Ostwald's "energetics" in discussing the connection of philosophical idealism with certain currents in new physics.

"We have already said," wrote Bogdanov in 1899, "that the nineteenth century did not succeed in finally settling the question of the 'unchanging essence of things.' This essence plays a prominent role even in the worldview of the most advanced thinkers of the century under the name of 'matter'…" (*Fundamental Elements of a Historical View of Nature*, p. 38).

We said that this is confusion. The recognition of the objective reality of the external world, the recognition of the existence outside our consciousness of eternally moving and eternally changing matter is confused here with the recognition of the unchanging essence of things. One cannot allow that Bogdanov in 1899 did not count among "advanced thinkers" Marx and Engels. But he clearly did not understand dialectical materialism.

"…In natural processes people still ordinarily distinguish two sides: matter and its motion. It cannot be said that the concept of matter is distinguished by great clarity. To the question what is matter – it is not easy to give a satisfactory answer. It is defined as a 'cause of sensations' or as a 'permanent possibility of sensations'; but it is evident that matter is confused here with motion…"

It is evident that Bogdanov reasons incorrectly. Moreover, not only does he confuse the materialist recognition of the objective source of sensations (stated unclearly in the words cause of sensations) with the agnostic Millian definition of matter as the permanent possibility of sensations. The basic error here is that the author, having approached closely to the question of the existence or non-existence of an objective source of sensations, abandons this question halfway and jumps to another question of the existence or non-existence of matter without motion. An idealist can consider the world the motion of our sensations (although "socially organized" and "harmonized" to the highest degree); a materialist – the motion of the objective source, the objective model of our sensations. A metaphysical, that is, anti-dialectical, materialist can accept the existence of matter (although temporary, before the "first push" and so on) without motion. A dialectical materialist not only considers motion an inseparable property of matter, but also rejects the simplified view of motion and so on.

"… The most precisely accurate definition, perhaps, would be this: 'matter is that which moves'; but this is just as empty of content as if we were to say: matter is the subject of a sentence, whose predicate is 'moves'. However, the point perhaps comes down to this, that people in the age of statics became accustomed to seeing in the role of subject necessarily something solid, some kind of 'object', and they agreed to tolerate only in the capacity of a predicate, as one of the attributes of 'matter', such an inconvenient thing for static thinking as 'motion'."

This is already something like Akimov's accusation of the Iskra adherents – that they have no word "proletariat" in the nominative case in their program! To say: the world is moving matter, or: the world is material motion – this does not change the matter.

"… But surely energy must have a bearer!" – say the defenders of matter. – "But why?" – Ostwald asks reasonably. – "Is nature obliged to consist of subject and predicate?" (p. 39).

Ostwald's answer, so pleasing to Bogdanov in 1899, is a simple sophism. One could answer Ostwald: are our judgments obliged to consist of electrons and ether? In fact, the mental elimination of matter as "subject" from "nature" means a silent admission of thought as "subject" (i.e., as something primary, original, independent of matter) into philosophy. What is eliminated is not the subject, but the objective source of sensation, and "subject" becomes sensation, i.e., philosophy becomes Berkeleian, no matter how one later disguises the word: sensation. Ostwald attempted to avoid this inevitable philosophical alternative (materialism or idealism) by means of the vague use of the word "energy", but precisely his attempt shows once more the futility of such stratagems. If energy is motion, then you have only shifted the difficulty from subject to predicate, only rephrased the question: does matter move? into the question: is energy material? Does the transformation of energy take place outside my consciousness, independently of man and mankind, or is it only ideas, symbols, conventional signs, etc.? On this question the "energeticist" philosophy has broken its neck – this attempt to cover up old epistemological errors with "new" terminology.

Here are examples of how muddled the energeticist Ostwald became. In the preface to his "Lectures on the Philosophy of Nature"[170] he declares that he considers it "a tremendous gain if the old difficulty: how to unite the concepts of matter and spirit – will be simply and naturally eliminated by subsuming both these concepts under the concept of energy". This is not a gain but a loss, because the question of whether to conduct epistemological investigation (Ostwald does not clearly realize that he is posing precisely an epistemological, not a chemical question!) in the materialist or idealist direction is not resolved but becomes entangled by the arbitrary use of the word "energy". Of course, if one "subsumes" under this concept both matter and spirit, then the verbal elimination of the opposition is undoubted, but the absurdity of the doctrine about wood-spirits and house-spirits will not disappear because we call it "energeticist". On p. 394 of Ostwald's "Lectures" we read: "That all external phenomena can be depicted as processes between energies, this circumstance is most simply explained by the fact that precisely the processes of our consciousness themselves are energetic and impress (aufprägen) this property of theirs upon all external experience". This is pure idealism: it is not our thought that reflects the transformation of energy in the external world, but the external world that reflects the "property" of our consciousness! The American philosopher Hibben speaks very aptly to this point, referring to this and other similar passages in Ostwald's lectures, saying that Ostwald "appears here in the guise of Kantianism": the intelligibility of external world phenomena is derived from the properties of our mind![171] "Clearly," says Hibben, "if we define the original concept of energy in such a way that it includes psychic phenomena, then it will no longer be that simple concept of energy which is recognized in scientific circles or even by the energeticists themselves". The transformation of energy is regarded by natural science as an objective process, independent of human consciousness and the experience of mankind, i.e., it is regarded materialistically. And even in Ostwald himself, in the majority of cases, probably in the vast majority of cases, energy means material motion.

Therefore, such an original phenomenon occurred: Ostwald's student, Bogdanov, becoming a student of Mach, began to accuse Ostwald not of the fact that he does not consistently maintain a materialist view of energy, but of the fact that he permits (sometimes even makes fundamental) a materialist view of energy. Materialists criticize Ostwald for lapsing into idealism, for attempting to reconcile materialism with idealism. Bogdanov criticizes Ostwald from an idealist standpoint: "… Ostwald's energetics, hostile to atomism but otherwise very akin to old materialism," writes Bogdanov in 1906, "attracted my warmest sympathies. Soon, however, I noticed an important contradiction in his philosophy of nature: while repeatedly emphasizing the purely methodological significance of the concept: energy – he himself does not maintain it in the majority of cases. Energy, from a pure symbol of relations between facts of experience, constantly transforms itself in him into a substance of experience, into the matter of the world…" ("Empiriomonism", book III, p. XVI–XVII).

Energy – a pure symbol! After this, Bogdanov may argue as much as he likes with the "empiriosymbolist" Yushkevich, with the "pure Machians", empiricritiques, etc., – from the standpoint of materialists this will be a dispute between a man who believes in a yellow devil and a man who believes in a green devil. For what matters is not Bogdanov's differences from other Machians, but what they have in common: the idealist interpretation of "experience" and "energy", the denial of objective reality, adaptation to which constitutes human experience, reflection of which constitutes the only scientific "methodology" and scientific "energetics".

"The material of the world is indifferent for it (Ostwald's energetics); it is fully compatible with both the old materialism and panpsychism" (XVII)… i.e., philosophical idealism? And Bogdanov went from confused energetics not along the materialist path but along the idealist path… "When energy is conceived as substance, this is nothing other than old materialism minus absolute atoms – materialism corrected in the sense of the continuity of existence" (ibid.). Yes, from "old" materialism, i.e., the metaphysical materialism of natural scientists, Bogdanov went not to dialectical materialism, which he understood in 1906 as little as in 1899, but to idealism and fideism, because against the "methodological" concept of energy, against its interpretation as a "pure symbol of relations between facts of experience", not a single educated representative of contemporary fideism, not a single immanentist, not a single "neocriticist", etc., will raise objections. Take P. Carus, with whose countenance we have become sufficiently acquainted above – and you will see that this Machian criticizes Ostwald in a thoroughly Bogdanovist manner: "Materialism and energetics," writes Carus, "belong unconditionally to one and the same category" ("The Monist", vol. XVII, 1907, № 4, p. 536). "Materialism enlightens us very little when it tells us that everything is matter, that bodies are matter, and that thought is only a function of matter; and Professor Ostwald's energetics is not the least bit better, since it tells us that matter is energy, and that soul is only a factor of energy" (533).

Ostwald's energetics is a good example of how quickly "new" terminology becomes fashionable and how quickly it turns out that a somewhat altered mode of expression does not at all eliminate the basic philosophical questions and basic philosophical tendencies. In the terms of "energetics" one can express materialism and idealism (more or less consistently, of course) just as well as in the terms of "experience" and the like. Energetic physics is the source of new idealist attempts to think motion without matter – following upon the decomposition of particles of matter previously thought indivisible and the discovery of previously unseen forms of material motion.

4. Two Directions in Modern Physics and English Spiritualism

To show concretely the philosophical struggle that has flared up in contemporary literature over various conclusions from the new physics, we shall give the floor to the direct participants in the "fray" and begin with the English. Physicist Arthur W. Ricker defends one direction – from the standpoint of a natural scientist; philosopher James Ward another – from the standpoint of epistemology.

At the congress of English natural scientists in Glasgow in 1901, the president of the physics section, A. W. Ricker, chose as the theme of his speech the question of the value of physical theory, about those doubts to which the existence of atoms and especially ether had been subjected. The speaker referred to physicists Poincaré and Poynting (English fellow-thinkers of the symbolists or Machians) who had raised this question, to the philosopher Ward, to the well-known book of E. Haeckel, and attempted to set forth his views.[172]

"The disputed question," said Ricker, "is whether those hypotheses which lie at the foundation of the most widespread scientific theories should be regarded as accurate descriptions of the structure of the world surrounding us, or only as convenient fictions". (In the terms of our dispute with Bogdanov, Yushkevich and Co.: is it a copy of objective reality, of moving matter, or only a "methodology", a "pure symbol", a "form of organizing experience"?) Ricker agrees that in practice there may be no difference between both theories: the direction of a river might be determined equally well by one who merely looks at a blue line on a map or diagram as by one who knows that this line represents an actual river. Theory, from the standpoint of convenient fiction, will be an "aid to memory", an "introduction of order" into our observations, a bringing of them into harmony with some artificial system, a "regulation of our knowledge", a reduction of it into equations, etc. One might, for example, be content to say that heat is a form of motion or energy, "thus replacing the vivid picture of moving atoms with a colorless (colourless) statement about thermal energy, the real nature of which we do not attempt to determine". While fully recognizing the possibility of major scientific successes along this path, Ricker "dares to assert that such a system of tactics cannot be regarded as the last word of science in the struggle for truth". The question remains in force: "can we infer from the phenomena exhibited by matter to the structure of matter itself"? "do we have grounds for believing that the outline of theory which science has already given is to some extent a copy, and not merely a diagram of truth"?

Examining the question of the structure of matter, Ricker takes air as an example, speaks of how air consists of gases and how science decomposes "every elementary gas into a mixture of atoms and ether". Here, he continues, we are told "Stop!". Molecules and atoms cannot be seen; they may be useful as "mere conceptions", "but they cannot be regarded as realities". Ricker dismisses this objection by reference to one of countless cases in the development of science: Saturn's rings appear in the telescope as a solid mass. Mathematicians proved by calculation that this is impossible, and spectral analysis confirmed conclusions drawn on the basis of calculations. Another objection: atoms and ether are ascribed properties which our senses do not show us in ordinary matter. Ricker dismisses this too, referring to examples such as diffusion of gases and liquids, etc. A series of facts, observations and experiments proves that matter consists of separate particles or grains. The question whether these particles, atoms, differ from the "primary medium", the "fundamental medium" surrounding them (ether), or whether they are parts of this medium in a special state, remains for now open, without touching the theory of the existence of atoms itself. There are no grounds for denying a priori, contrary to the indications of experience, the existence of "quasi-material substances" distinct from ordinary matter (atoms and ether). Errors in particulars are here inevitable, but the whole body of scientific data leaves no room for doubt regarding the existence of atoms and molecules.

Ricker then points to new data about the structure of atoms from corpuscles (particles, electrons) charged with negative electricity, and notes the similarity of results of various experiments and calculations concerning the size of molecules: the "first approximation" gives a diameter of about 100 millimicrons (millionths of a millimeter). Passing over Ricker's particular remarks and his critique of neo-vitalism{84}, we present his conclusions:

"Those who diminish the significance of the ideas that have guided scientific theory's progress hitherto too often assume that there is no choice except between two opposite assertions: either that the atom and ether are mere fictions of scientific imagination, or that the mechanical theory of atoms and ether – now it is not complete, but if it could be completed – gives us a full and ideally accurate representation of realities. In my opinion, there is a middle way". A man in a dark room may very dimly discern objects, but if he does not collide with furniture and does not walk into a mirror as if it were a door, then he is seeing something correctly. We therefore need neither renounce the claim to penetrate deeper than the surface of nature, nor claim that we have already torn away all the veils of mystery from the world surrounding us. "One may agree that we have not yet formed a completely integral picture either of the nature of atoms or of the nature of the ether in which they exist; but I have attempted to show that, despite the tentative (tentative, literally: probing) character of some of our theories, despite many particular difficulties, the theory of atoms… in its main foundations is correct; that atoms are not merely auxiliary concepts (helps) for mathematicians, but physical realities".

Thus Ricker concluded his speech. The reader sees that the speaker did not occupy himself with epistemology, but by virtue of his position, speaking for what was undoubtedly the majority of natural scientists, he spontaneously defended the materialist standpoint. The essence of his position: physical theory is a copy (ever more accurate) of objective reality. The world is moving matter, which we come to know ever more profoundly. The inaccuracies in Ricker's philosophy flow from the unnecessary defense of the "mechanical" (why not electromagnetic?) theory of the motions of the ether and from a failure to understand the relationship between relative and absolute truth. This physicist lacks only knowledge of dialectical materialism (not counting, of course, those very important practical considerations that compel English professors to call themselves "agnostics").

Let us now see how this philosophy was criticized by the spiritualist James Ward. "… Naturalism is not science," he wrote, "and the mechanical theory of nature, which serves as its foundation, is not science either… But although naturalism and natural science, the mechanical theory of the world and mechanics as a science, are logically distinct things, at first glance they seem very similar to one another and are historically closely connected. There is no danger that natural science will be confused with philosophy of an idealist or spiritualist direction, since such philosophy necessarily includes a critique of the epistemological presuppositions which science makes unconsciously…"[173]. True! Natural science unconsciously assumes that its doctrine reflects objective reality, and only such philosophy is compatible with natural science! "… The case is different with naturalism, which is just as innocent of epistemological theory as science itself. In fact, naturalism, like materialism, is simply physics treated as metaphysics… Naturalism is less dogmatic than materialism, undoubtedly, since it makes agnostic reservations concerning the nature of ultimate reality; but it insists decisively on the primacy of the material side of this 'Unknowable'…"

The materialist treats physics as metaphysics. A familiar argument! Metaphysics is called the recognition of objective reality outside man: spiritualists agree with Kantians and Humeans in such reproaches to materialism. It is understandable: without eliminating the objective reality of things universally known to all, bodies, objects, one cannot clear the way for "real concepts" in the manner of Remke!..

"… When there arises a question that is philosophical in nature, such as how best to systematize experience as a whole" (plagiarism from Bogdanov, Mr. Ward!), "the naturalist insists that we must begin with the physical side. Only these facts are precise, determinate and strictly connected; every thought that has stirred the human heart… can, we are told, be reduced to a perfectly precise redistribution of matter and motion… That assertions of such philosophical significance and such breadth are legitimate conclusions from physical science (i.e., natural science), present-day physicists do not venture to assert directly. But many of them consider it undermining the significance of science when people strive to expose the hidden metaphysics, to expose the physical realism on which the mechanical theory of the world rests…" So-de looked upon my philosophy, they say, even Ricker. "… But in reality, my critique" (of this "metaphysics", hateful to all Machians) "is based entirely on the conclusions of the school of physicists, if one may so call it, ever growing in number and expanding in influence, a school which rejects this almost medieval realism… This realism has for so long met with no objections that uprising against it is equated with proclaiming scientific anarchy. Yet it would be truly extravagant to suspect such men as Kirchhoff and Poincaré – I name only two major names from many – of wishing to 'undermine the significance of science'… To distinguish them from the old school, which we are right to call physical realists, we may call the new school physical symbolists. The term is not entirely felicitous, but it at least emphasizes one essential difference between both schools, which interests us specifically at this time. The disputed question is very simple. Both schools proceed, it is understood, from the same sensual (perceptual) experience; both employ abstract systems of concepts, differing in particulars but identical in essence; both resort to the same methods of verifying theories. But one believes that it is drawing ever closer and closer to ultimate reality and leaving behind ever more appearances. The other believes that it is substituting (is substituting) generalized descriptive schemas, suitable for intellectual operations, for complex concrete facts… Neither side has the question raised concerning the value of physics as a systematic knowledge of (italics Ward's) things; the possibility of further development of physics and its practical applications is the same in both cases. But the philosophical (speculative) difference between both schools is enormous, and in this respect the question of which of them is right acquires importance…".

The framing of the question by an open and consistent spiritualist is remarkably apt and clear. Indeed, the difference between both schools in contemporary physics is only philosophical, only epistemological. Indeed, the basic difference consists only in the fact that one recognizes "ultimate" (should be said: objective) reality reflected by our theory, while the other denies this, considering theory only a systematization of experience, a system of empiriosymbols, etc. The new physics, having found new types of matter and new forms of its motion, has raised the old philosophical questions on occasion of the breakdown of old physical concepts. And if people of "middle" philosophical tendencies ("positivists", Humeans, Machians) are unable to pose the disputed question distinctly, then the open idealist Ward has thrown off all veils.

"… Ricker devoted his presidential address to defending physical realism against the symbolic interpretation, which has been defended of late by Professors Poincaré, Poynting and myself" (p. 305–306; in other places in his book Ward adds to this list Duhem, Pearson and Mach, see II vol., p. 161, 63, 57, 75, 83, etc.).

"… Ricker constantly speaks of 'mental images' and at the same time constantly asserts that the atom and ether are something more than mental images. Such a method of argumentation in fact amounts to the following: in such-and-such a case I cannot form any other image, and therefore reality must resemble it… Professor Ricker recognizes the abstract possibility of another mental image… He even admits the 'tentative' character of some of our theories and many 'particular difficulties'. In the end he defends only a working hypothesis (a working hypothesis), and such a one at that which has lost a good deal of its prestige over the last half century. But if the atomic and other theories of the structure of matter are only working hypotheses, and moreover hypotheses strictly limited to physical phenomena, then there is nothing to justify the theory asserting that mechanism is the foundation of everything and that it reduces the facts of life and spirit to epiphenomena, that is, making them, so to speak, one degree more phenomenal, one degree less real than matter and motion. Such is the mechanical theory of the world, and if Professor Ricker will not directly support it, then we have nothing to dispute with him" (p. 314–315).

This is, of course, sheer nonsense, as if materialism asserted the "lesser" reality of consciousness or necessarily a "mechanical", rather than electromagnetic, or any other immeasurably more complex picture of the world as moving matter. But it is truly with a juggler's sleight of hand that the open and forthright idealist Ward, far better than our Machians (i.e., confused idealists) – seizes upon the weak spots of "spontaneous" natural-historical materialism, for example, the inability to explain the relationship between relative and absolute truth. Ward tumbles about and declares that if truth is relative, approximate, only "groping" toward the matter – then it cannot reflect reality! Extremely well posed, on the other hand, is the question raised by the spiritualist regarding atoms, etc., as a "working hypothesis". Contemporary, educated fideism (Ward directly derives it from his spiritualism) thinks nothing more and demands nothing more than declaring the concepts of natural science "working hypotheses". We will give you science, gentlemen natural scientists, give us epistemology, philosophy – such is the condition of cohabitation of theologians and professors in "advanced" capitalist countries.

As for other points of Ward's epistemology connected by him with "new" physics, here we must also mention his decisive struggle against matter. What is matter? What is energy? Ward asks, ridiculing the abundance and contradictoriness of hypotheses. Ether or ethers? some new "perfect fluid" to which one arbitrarily attributes new and incredible properties! And Ward's conclusion: "We find nothing definite except motion. Heat is a kind of motion, elasticity is a kind of motion, light and magnetism are a kind of motion. Mass itself turns out in the end, as is supposed, to be a kind of motion – the motion of something that is neither solid body nor liquid nor gas – itself not a body and not an aggregate of bodies – not phenomenal and should not be noumenal – true apeiron[174] (a term from Greek philosophy = the infinite, the boundless), to which we can apply our own characteristics" (I, 140).

The spiritualist is true to himself, severing motion from matter. The motion of bodies transforms in nature into the motion of what is not a body with constant mass, into the motion of what is an unknown charge of unknown electricity in an unknown ether – this dialectic of material transformations, carried out in the laboratory and the factory, serves in the eyes of the idealist (and in the eyes of the general public, and in the eyes of the Machians) as confirmation not of materialist dialectics but as an argument against materialism: "… The mechanical theory, as a professed explanation of the world, receives a mortal blow from the progress of mechanical physics itself" (143)… The world is moving matter, we answer, and the laws of motion of this matter are reflected by mechanics with respect to slow motions, by electromagnetic theory with respect to fast motions… "The extended, solid, indestructible atom has always been the mainstay of the materialist view of the world. But, unfortunately for these views, the extended atom did not satisfy the demands which growing knowledge made upon it" (144)… The destructibility of the atom, its inexhaustibility, the changeability of all forms of matter and its motion have always been the mainstay of dialectical materialism. All boundaries in nature are conditional, relative, mobile, expressing the approximation of our mind to knowledge of matter – but this in no way proves that nature, matter itself is a symbol, a conventional sign, i.e., a product of our mind. The electron stands to the atom as a point in this book to the volume of a building 30 sazhens in length, 15 in width, and 7½ in height (Lodge), it moves at a velocity up to 270,000 kilometers per second, its mass changes with its velocity, it makes 500 trillion revolutions per second – all this is much more complex than old mechanics, but all this is the motion of matter in space and time. The human mind has discovered much that is wonderful in nature and will discover still more, thereby increasing its power over it, but this does not mean that nature was created by our mind or by abstract mind, i.e., by Ward's god, by Bogdanov's "substitution", etc. "… Strictly (rigorously) carried through, as a theory of the real world, this ideal (the ideal of "mechanism") leads us to nihilism: all changes are motions, because motions are the only changes we can know, and what moves, in order to be known to us, must again be motion" (166)… "As I have attempted to show, the progress of physics proves to be precisely the most powerful means of struggle against ignorant belief in matter and motion, against recognition of them as the ultimate (inmost) substance, rather than the most abstract symbol for the sum of existence… We shall never reach god through bare mechanism" (180)…

Well, this is now going just like in the "Essays 'on' the Philosophy of Marxism"! You might try to appeal, Mr. Ward, to Lunacharsky and Yushkevich, Bazarov and Bogdanov: they are at least more shy than you, but they preach precisely the same thing.

5. Two Directions in Modern Physics and German Idealism

In 1896, with extraordinary solemn exultation, the well-known Kantian idealist Hermann Cohen appeared in the preface to the 5th edition of the "History of Materialism", falsified by Fr. Albert Lange. "Theoretical idealism," exclaimed H. Cohen (S. XXVI), "has begun to shake materialism of natural scientists and, perhaps, will soon finally defeat it". "Idealism permeates (Durchwirkung) the new physics". "Atomism had to yield place to dynamism". "The remarkable turn consists in the fact that penetration into chemical problems of substance was destined to lead to the principled overcoming of the materialist view of matter. Just as Thales produced the first abstraction, isolating the concept of substance and connecting with it speculative reflections on the electron, so the theories of electricity were destined to produce the greatest transformation in the understanding of matter and, through the transformation of matter into force, to lead to the victory of idealism" (XXIX).

H. Cohen, just as clearly and distinctly as J. Ward, marks out the fundamental philosophical tendencies, without getting lost (as our Machians get lost) in the trifling differences of some energeticist, symbolist, empiricritical, empiriomonistic, etc., idealism. Cohen seizes upon the fundamental philosophical tendency of that school in physics which is now connected with the names of Mach, Poincaré, and others, correctly characterizing this tendency as idealist. "The transformation of matter into force" appears here to Cohen as the chief conquest of idealism – precisely as it did for those natural scientists-"visionaries of spirits" whom I. Dietzgen exposed in 1869. Electricity is proclaimed a collaborator of idealism, because it destroyed the old theory of the structure of matter, decomposed the atom, revealed new forms of material motion so unlike the old ones, so still unexplored, unstudied, unusual, "miraculous", that one can smuggle in an interpretation of nature as immaterial (spiritual, mental, psychic) motion. Yesterday's limit of our knowledge of infinitesimally small particles of matter has disappeared – consequently, concludes the idealist philosopher – matter has disappeared (and thought remained). Every physicist and every engineer knows that electricity is (material) motion, but no one knows precisely what is moving – consequently, concludes the idealist philosopher – one can hoodwink the philosophically uneducated with a seductively "economical" proposal: let us think motion without matter…

H. Cohen attempts to recruit the famous physicist Heinrich Hertz to his side. Hertz is ours, he is a Kantian, in him there crops up an a priori assumption! Hertz is ours, he is a Machian, – disputes the Machian Kleinpeter – because in Hertz shows through "that same subjectivist view, as in Mach, on the essence of our concepts"[175]. This curious dispute about whose Hertz is gives a good sample of how idealist philosophers catch the slightest error, the slightest obscurity in the expression of famous natural scientists in order to justify their updated defense of fideism. In fact, the philosophical introduction of H. Hertz to his "Mechanics"[176] shows the usual point of view of a natural scientist frightened by professorial howling against the "metaphysics" of materialism, but in no way able to overcome the spontaneous conviction in the reality of the external world. Even Kleinpeter admits this, on the one hand scattering among the mass of readers thoroughly false popular brochures on the epistemology of natural science, with Mach figuring side by side with Hertz – on the other hand, in special philosophical articles admitting that "Hertz, in contrast to Mach and Pearson, still holds the prejudice concerning the possibility of mechanically explaining all physics"[177], that he retains the concept of a thing-in-itself and the "usual standpoint of physicists", that Hertz "still held to the existence of the world in itself"[178], etc.

It is interesting to note Hertz's view on energetics. "If we," he wrote, "ask why, precisely, modern physics loves to employ the energetic mode of expression in its arguments, then the answer will be this: because in this way one can most conveniently avoid having to speak of things about which we know very little… Of course, we are all convinced that ponderable matter consists of atoms; about their magnitude and their motions in certain cases we have fairly definite conceptions. But the form of atoms, their cohesion, their motions in the majority of cases are completely hidden from us… Therefore our conceptions of atoms constitute an important and interesting objective for further research, being in no way especially suited to serve as a firm foundation for mathematical theories" (l. c, III, 21). Hertz awaited from further study of the ether a clarification of "the nature of old matter, its inertia and the force of gravitation" (I, 354).

From this it is evident that Hertz did not even have the idea of the possibility of a non-materialist view of energy. For philosophers, energetics served as a reason for flight from materialism to idealism. The natural scientist looks upon energetics as a convenient way of expounding the laws of material motion at such a time when physicists have, so to speak, departed from the atom but not yet reached the electron. This time continues to a considerable degree even now: one hypothesis is replaced by another; about the positive electron virtually nothing is known; only three months ago (June 22, 1908) Jean Becquerel reported to the French Academy of Sciences that he had succeeded in finding this "new component part of matter" ("Comptes rendus des séances de l'Académie des Sciences", p. 1311[179]). How then not to take advantage of idealist philosophy in such a convenient circumstance, that "matter" is only still being "sought" by the human mind – consequently, it is nothing more than a "symbol", etc.

Another German idealist, of a far more reactionary tendency than Cohen, Eduard von Hartmann, devoted an entire book to "The Worldview of Modern Physics" ("Die Weltanschauung der modernen Physik", Lpz., 1902). We are not interested, of course, in the author's special arguments for that variant of idealism which he defends. We need only point out that this idealist too has established the same phenomena which have been established by Ricker, Ward, and Cohen. "Modern physics has grown on realistic soil," says E. Hartmann, "and only the neo-Kantian and agnostic current of our epoch has led to the final results of physics being interpreted in an idealist sense" (218). Three epistemological systems, according to E. Hartmann, lie at the foundation of modern physics: hylokinetics (from the Greek words hyle = matter and kinesis = motion – i.e., recognition of physical phenomena as motion of matter), energetics and dynamism (i.e., recognition of force without substance). It is clear that the idealist Hartmann defends "dynamism", deduces from this that the laws of nature are universal thought, in a word, "substitutes" the psychic for physical nature. But he is forced to admit that hylokinetics has on its side the majority of physicists, that this system "is most frequently employed" (190), that a serious deficiency of it is the "materialism and atheism threatening pure hylokinetics" (189). The author regards energetics quite justly as an intermediate system and calls it agnosticism (136). Of course, it is "an ally of pure dynamism, because it eliminates substance" (S. VI, p. 192), but its agnosticism does not please Hartmann, as a certain "Anglophilia" contradicting the true idealism of a genuinely German reactionary.

It is extremely instructive to see how this partisanly uncompromising idealist (disinterested people in philosophy are just as hopeless fools as in politics) explains to physicists what precisely it means to proceed along this or that epistemological line. "The vast majority of those physicists who engage in this fashion," writes Hartmann of the idealist interpretation of the latest results of physics, "are not fully conscious of all the significance and all the consequences of such interpretation. They have not noticed that physics with its special laws only maintains its independent significance insofar as physicists, in spite of their idealism, held to realistic basic presuppositions, namely: the existence of things-in-themselves, their actual changeability in time, actual causality… Only under these realistic presuppositions (of transcendental significance of causality, time, space with three dimensions), i.e., only on condition that the nature about whose laws physics speaks coincides with the realm of things-in-themselves… can one speak of laws of nature in distinction from psychological laws. Only if the laws of nature operate in a sphere independent of our thinking can they serve as an explanation of the fact that logically necessary conclusions from our images turn out to be images of naturally-historically-necessary results of that Unknown which these images reflect or symbolize in our consciousness" (218–219).

Hartmann correctly senses that the idealism of the new physics is precisely a fashion, not a serious philosophical turn away from natural-historical materialism, and he correctly explains to physicists therefore that for transforming the "fashion" into a consistent, whole philosophical idealism, one must radically rework the doctrine of the objective reality of time, space, causality and the laws of nature. It is not enough to consider only atoms, electrons, ether as mere symbols, mere "working hypotheses" – one must declare time, space, the laws of nature, and the entire external world "working hypotheses". Either materialism or universal substitution of the psychic for all physical nature; to mix these two trades there are plenty of hunters, but we are not of their number along with Bogdanov.

From among German physicists, the one who systematically struggled against the Machian current was Ludwig Boltzmann, who died in 1906. We have already indicated that he opposed the "fascination with new epistemological dogmas" with the simple and clear reduction of Machism to solipsism (see above, ch. I, § 6). Boltzmann, of course, fears to call himself a materialist and even specially notes that he is not at all against the existence of God[180]. But his epistemology is in essence materialist, and expresses it – as the historian of natural sciences in the 19th century S. Günther acknowledges[181] – the opinion of the majority of natural scientists. "We come to know the existence of all things from the impressions," says L. Boltzmann, "which they produce on our senses" (l. c, S. 29). Theory is an "image" (or: copy) of nature, of the external world (77). To those who say that matter is only a complex of sensory sensations, Boltzmann points out that then other people too are only sensations of the speaker (168). These "ideologists", as Boltzmann sometimes says instead of: philosophical idealists, depict for us a "subjective picture of the world" (176), while the author prefers a "simpler objective picture of the world". "The idealist compares the assertion that matter exists just as our sensations do with the opinion of a child that a beaten stone experiences pain. The realist compares the opinion that one cannot imagine the origin of the psychic from the material or even from the play of atoms with the opinion of an uneducated man who asserts that the sun cannot be 20 million miles from the earth because he cannot imagine it" (186). Boltzmann does not renounce the ideal of representing spirit and will as "complex actions of particles of matter" (396).

Against Ostwald's energetics, L. Boltzmann conducted polemics repeatedly from the standpoint of a physicist, proving that Ostwald can neither refute nor eliminate the formulas of kinetic energy (half the mass multiplied by the square of velocity) and that he turns in a vicious circle, first deriving energy from mass (accepting the formula of kinetic energy) and then defining mass as energy (S. 112, 139). In this connection I am reminded of Bogdanov's restatement of Mach in the third book of "Empiriomonism". "In science," writes Bogdanov, referring to Mach's "Mechanics", "the concept of matter is reduced to the coefficient of mass that appears in the equations of mechanics, and this latter, upon precise analysis, turns out to be the reciprocal magnitude of acceleration in the interaction of two physical complexes – bodies" (p. 146). It is understandable that if one body is taken as the unit, the motion (mechanical) of all other bodies can be expressed as a simple relation of acceleration. But even after this, "bodies" (i.e., matter) do not at all cease to exist, do not cease to exist independently of our consciousness. When the entire world is reduced to the motion of electrons, electrons can be eliminated from all equations precisely because they will be understood everywhere, and the relation of groups or aggregates of electrons will be reduced to their mutual acceleration – if only the forms of motion were as simple as in mechanics.

In struggling against the "phenomenological" physics of Mach and Co., Boltzmann asserted that "those who think to eliminate atomistics by means of differential equations do not see the forest for the trees" (144). "If one does not delude oneself about the significance of differential equations, then there can be no doubt that the picture of the world (by means of differential equations) will nonetheless necessarily be atomistic, a picture of how vast quantities of things, arranged in space with three dimensions, will change according to certain rules in time. These things can, of course, be the same or different, unchangeable or changeable" and so forth (156). "It is perfectly evident that phenomenological physics only clothes itself in the garment of differential equations," says Boltzmann in 1899 in a speech at the Munich congress of natural scientists, "but in fact it proceeds equally from atom-like separate entities (Einzelwesen). And since these entities must be represented as possessing one or another property for different groups of phenomena, the need for simpler and more uniform atomistics will soon manifest itself" (223). "The doctrine of electrons develops precisely into an atomistic theory of all electrical phenomena" (357). The unity of nature reveals itself in the "striking analogy" of differential equations pertaining to different domains of phenomena. "The very same equations can solve questions of hydrodynamics and express the theory of potentials. The theory of vortices in liquids and the theory of friction of gases (Gasreibung) reveal striking analogy with the theory of electromagnetism, etc." (7). People who recognize the "theory of universal substitution" will in no way be able to avoid the question: who then so uniformly guessed to "substitute" physical nature.

# [Part 3/4]

As if in reply to people who brush off "physics of the old school," Boltzmann provides a detailed account of how certain specialists in "physical chemistry" adopt an epistemological standpoint opposed to Machism. The author of "one of the best," according to Boltzmann, comprehensive works of 1903, Vaubel, "assumes a decisively hostile attitude toward the so often praised phenomenological physics" (381). "He endeavors to form as concrete and vivid a conception as possible of the nature of atoms and molecules and of the forces acting between them. This conception he adapts to the latest experimental findings in this field" (ions, electrons, radium, the Zeeman effect, etc.). "The author strictly adheres to the dualism of matter and energy[182], expounding separately the law of conservation of matter and the law of conservation of energy. With respect to matter, the author likewise maintains a dualism of ponderable matter and ether, but the latter he regards in the most strict sense as material" (381). In the second volume of his work (theory of electricity), the author "from the very beginning assumes the standpoint that electrical phenomena are caused by the interaction and motion of atom-like individuals, namely electrons" (383). Consequently, as regards Germany too, that is confirmed which, as regards England, was acknowledged even by the spiritualist J. Ward, namely: that physicists of the realist school systematize facts and discoveries of recent years no less successfully than physicists of the symbolist school, and that the essential difference consists "only" in the epistemological standpoint[183].

6. Two Tendencies in Contemporary Physics and French Fideism

In France, idealist philosophy seized no less decisively upon the wavering of Machist physics. We have already seen how the neo-critics received Mach's "Mechanics," at once noting the idealist character of the foundations of Mach's philosophy. The French Machist Poincaré (Henri) had even greater success in this respect. The most reactionary idealist philosophy with distinctly fideistic conclusions immediately seized upon his theory. A representative of this philosophy, Le Roy, reasoned as follows: the truths of science are conventional signs, symbols; you have abandoned the absurd, "metaphysical" pretensions to knowledge of objective reality; be consistent then and agree with us that science has only practical significance for one sphere of human activity, while religion has significance no less real than science for another sphere of activity; science—symbolic, Machist science—has no right to deny theology. A. Poincaré was ashamed of these conclusions and in his book "The Value of Science" specially attacked them. But observe what epistemological position he was forced to adopt in order to free himself from such allies as Le Roy. "Mr. Le Roy," writes Poincaré, "declares reason hopelessly impotent solely in order to make more room for other sources of knowledge—for the heart, feeling, instinct, faith" (214–215). "I do not go to that extent": scientific laws are conventions, symbols, but "if scientific 'recipes' have value as a rule for action, it is because on the whole, as we know, they succeed. To know this means to know something already, and if that is so, what right have you to tell us that we can know nothing?" (219).

A. Poincaré appeals to the criterion of practice. But he thereby only shifts the question, not resolves it, for this criterion can be interpreted both in a subjective and in an objective sense. Le Roy too accepts this criterion for science and industry; he only denies that this criterion proves objective truth, for such denial suffices for him to recognize the subjective truth of religion alongside the subjective (non-existent apart from humanity) truth of science. A. Poincaré sees that one cannot limit oneself to appealing to practice against Le Roy, and he proceeds to the question of the objectivity of science. "What is the criterion of the objectivity of science? The very same as the criterion of our belief in external objects. These objects are real insofar as the sensations which they arouse in us appear to us united, I know not by what sort of indestructible cement, and not by chance of the day" (269–270).

That the author of such reasoning can be an eminent physicist is admissible. But it is beyond all dispute that only Voroshilovs-Yushkevichs can take him seriously as a philosopher. They declared materialism destroyed by a "theory" which at the first onslaught of fideism takes refuge under the wing of materialism! For this is the purest materialism if you hold that sensations are aroused in us by real objects and that "faith" in the objectivity of science is the same as "faith" in the objective existence of external objects.

"…One can say, for example, that the ether possesses no less reality than any external body whatsoever" (270).

What an outcry the Machists would raise if a materialist had said this! How many toothless witticisms there would be about "ethereal materialism" and the like. But the founder of the latest empirio-symbolism, five pages later, pronounces: "All that is thought is pure nothingness; for we cannot think anything except thought" (276). You are mistaken, Mr. Poincaré: your works prove that there exist people who can think only nonsense. To this category belongs the notorious muddler Georges Sorel, who asserts that "the first two parts" of Poincaré's book on the value of science "are written in the spirit of Le Roy" and that therefore both these philosophers can "be reconciled" on the following: the attempt to establish identity between science and the world is an illusion; one need not raise the question whether science can know nature; it suffices that science correspond with the mechanisms created by us (Georges Sorel: "Les préoccupations métaphysiques des physiciens modernes", P., 1907, p. 77, 80, 81[184]).

But if Poincaré's "philosophy" merely needs to be noted and passed by, then A. Rey's work demands detailed examination. We have already indicated that the two main tendencies in contemporary physics, which Rey calls "conceptualist" and "neo-mechanist," reduce to the difference between idealist and materialist epistemology. We must now see how the positivist Rey resolves a task diametrically opposite to that of the spiritualist J. Ward, the idealists G. Cohen and E. Hartmann—namely: not to embrace the philosophical errors of the new physics, its deviation toward idealism, but to correct these errors, to prove the illegitimacy of the idealist (and fideistic) conclusions from the new physics.

Through all of Rey's work there runs like a red thread the acknowledgment of the fact that fideism (p. II, 17, 220, 362, etc.) and "philosophical idealism" (200), skepticism regarding the rights of Reason and science (210, 220), subjectivism (311), etc., have seized upon the new theory of physics by the "conceptualists" (Machists). And therefore Rey rightly makes the center of his work a thorough analysis of "the opinions of physicists regarding the objective value of physics" (3).

What, then, are the results of this analysis?

Let us take the fundamental concept—the concept of experience. Rey assures us that Mach's subjectivist interpretation (let us take him for simplicity and brevity as the representative of the school which Rey calls conceptualist) is a mere misunderstanding. It is true that among the "chief new features of the philosophy of the late nineteenth century" belongs the fact that "empiricism, ever more refined, ever richer in nuances, leads to fideism, to the recognition of the primacy of faith—empiricism that once was a great weapon in skepticism's struggle against the assertions of metaphysics. Did this not occur because, in essence, by imperceptible nuances, little by little, the real meaning of the word 'experience' was distorted? In reality, experience, if taken in its conditions of existence, in that experimental science which determines it and refines it—experience leads us to necessity and to truth" (398). It is undeniable that all Machism, in the broad sense of the word, is nothing other than a distortion through imperceptible nuances of the real meaning of the word "experience"! But how does Rey correct this distortion, accusing only the fideists and not Mach himself of the distortion? Listen: "Experience, by the usual definition, is knowledge of an object. In physical science this definition is more apt than anywhere else… Experience is that over which our mind has no power, which our desires and will cannot alter—that which is given, which we do not create. Experience is the object opposite to (en face du) the subject" (314).

There you have a specimen of Rey's defense of Machism! How brilliantly perspicacious was Engels when he characterized the newest type of supporters of philosophical agnosticism and phenomenalism with the epithet: "shamefaced materialists." The positivist and ardent phenomenalist Rey is an excellent specimen of this type. If experience is "knowledge of an object," if "experience is the object opposite the subject," if experience consists in the fact that "something external (quelque chose du dehors) exists and exists necessarily" (se pose et en se posant s'impose, p. 324)—then this obviously reduces to materialism! Rey's phenomenalism, his most assiduous emphasis that there is nothing but sensations, that the objective is the universally valid, etc., etc.—all this is a fig leaf, empty verbal concealment of materialism, once we are told:

"Objective is that which is given us from without, imposed (imposé) by experience; that which we do not produce, which is produced independent of us and which to some degree produces us" (320). Rey defends "conceptualism" by destroying conceptualism! The refutation of idealist conclusions from Machism is achieved only by interpreting Machism in the sense of shamefaced materialism. Having himself acknowledged the distinction between two tendencies in contemporary physics, Rey labors strenuously to efface all distinctions in favor of the materialist tendency. For example, regarding the neo-mechanist school Rey says that it permits "not the slightest doubt, not the slightest uncertainty" on the question of the objectivity of physics (237): "here (i.e., on the basis of this school's doctrines) you are far from all those roundabout paths through which you were forced to go from the standpoint of other theories of physics in order to arrive at the assertion of this objectivity."

These very "roundabout paths" of Machism Rey covers over, drapes with a veil throughout his exposition. The fundamental characteristic of materialism is precisely that it proceeds from the objectivity of science, from the recognition of objective reality reflected by science, whereas idealism needs "roundabout paths" in order somehow to "derive" objectivity from spirit, consciousness, from the "psychical." "The neo-mechanist (i.e., dominant) school in physics," writes Rey, "believes in the reality of physical theory in the same sense in which mankind believes in the reality of the external world" (p. 234, § 22: thesis). For this school "theory wishes to be a tracing (le décalque) of the object" (235).

Correct. And this fundamental characteristic of the "neo-mechanist" school is nothing other than the basis of materialist epistemology. No denials by Rey of the materialists, no assurances of his that the neo-mechanists too are essentially phenomenalists, etc., can weaken this cardinal fact. The essence of the difference between neo-mechanists (materialists more or less shamefaced) and Machists consists precisely in this: the latter retreat from such a theory of knowledge, and in retreating from it, inevitably stumble into fideism.

Take Rey's treatment of Mach's doctrine on causality and necessity in nature. Only at first glance, Rey assures us, does Mach "approach skepticism" (76) and "subjectivism" (76); this "ambiguity" (équivoque, p. 115) is dispelled if one takes Mach's doctrine as a whole. And Rey takes it as a whole, adduces a series of quotations both from "The Science of Heat" and from "The Analysis of Sensations," specially dwells on the chapter on causality in the first of the named works—but…but he carefully avoids citing the decisive passage, Mach's assertion that there is no physical necessity, but only logical necessity! To this one can only say that this is not an interpretation but a whitewashing of Mach, that this is an effacement of distinctions between "neo-mechanism" and Machism. Rey's conclusion: "Mach continues the analysis and accepts the conclusions of Hume, Mill, and all phenomenalists, according to whose view causality contains nothing substantial in itself and appears only as a habit of thought. Mach accepts the fundamental thesis of phenomenalism, in relation to which the doctrine of causality is merely a consequence, namely: that nothing exists but sensations. But Mach adds in a purely objectivist direction: science, in investigating sensations, finds in them constant and universal elements which, being abstracted from sensations, have the same reality as the sensations themselves, since they are drawn from sensations by means of sense observation. And these constant and universal elements, such as energy and its transformations, form the basis of the systematization of physics" (117).

It turns out that Mach accepts Hume's subjective theory of causality and interprets it in an objectivist sense! Rey evades the issue, defending Mach by references to his inconsistency and leading to the conclusion that in the "real" interpretation of experience, this experience leads to "necessity." And experience is that which is given from without, and if the necessity of nature, its laws, are also given to man from without, from objectively real nature—then, of course, all difference between Machism and materialism disappears. Rey defends Machism from "neo-mechanism" by capitulating along the whole line before the latter, upholding the little word phenomenalism rather than the essence of this tendency.

Poincaré, for instance, in perfect Machist spirit derives the laws of nature—down to the fact that space has three dimensions—from "convenience." But this by no means signifies "arbitrary," Rey hastens to "correct." No, "convenient" expresses here {{adaptation to the object" (italics Rey's, p. 196). Nothing to say, a splendid distinction between the two schools and a "refutation" of materialism… "If Poincaré's theory is separated by a logically impassable gulf from the ontological interpretation of the mechanist school" (i.e., from this school's recognition that theory is a tracing of the object)…"if Poincaré's theory is capable of serving as a support for philosophical idealism, then at least on the ground of science it agrees very well with the general development of ideas of classical physics, with the tendency to regard physics as objective knowledge, as objective as experience itself, i.e., as the sensations from which experience proceeds" (200).

On the one hand, one cannot but confess; on the other hand, one must confess. On the one hand, an impassable gulf separates Poincaré from neo-mechanism, although Poincaré stands midway between Mach's "conceptualism" and neo-mechanism, while Mach is supposedly not separated from neo-mechanism by any gulf at all. On the other hand, Poincaré is fully in accord with classical physics, which, by Rey's own words, stands entirely on the standpoint of "mechanism." On the one hand, Poincaré's theory is capable of serving as a support for philosophical idealism; on the other hand, it is compatible with an objective interpretation of the word "experience." On the one hand, these wretched fideists distorted the meaning of the word "experience" by imperceptible deviations, retreating from the correct view that "experience is the object"; on the other hand, the objectivity of experience means only that experience is sensations—with which Berkeley and Fichte agree perfectly!

Rey got tangled up because he set himself an insoluble task: to "reconcile" the contradiction between the materialist and idealist schools in the new physics. He attempts to weaken the materialism of the neo-mechanist school by subsumes under phenomenalism the views of physicists who consider their theory a tracing of the object[185]. And he attempts to weaken the idealism of the conceptualist school by cutting out the most decisive statements of its supporters and interpreting the rest in the sense of shamefaced materialism. To what degree his renunciation of materialism is fictitious and strained is shown, for instance, by his evaluation of the theoretical significance of Maxwell's and Hertz's differential equations. For Machists, the fact that these physicists limit their theory to a system of equations is a refutation of materialism: equations—and that is all, no matter, no objective reality, only symbols. Boltzmann refutes this view, understanding that he is refuting phenomenological physics. Rey refutes it while thinking he is defending phenomenalism! "One cannot refuse," he says, "to number Maxwell and Hertz among the 'mechanists' on the ground that they limited themselves to equations, similar to differential equations in Lagrange's dynamics. This does not mean that, in the opinion of Maxwell and Hertz, we cannot construct a mechanical theory of electricity on real elements. On the contrary, the possibility of this is proved by the fact that electrical phenomena are represented by a theory whose form is identical with the general form of classical mechanics" (253)… The indefiniteness in the present solution of the problem "will decrease as the nature of those quantitative units, i.e., elements, which enter into the equations, becomes more clearly defined." The investigatedness of this or that form of material motion is not for Rey a reason for denying the materiality of motion. "The homogeneity of matter" (262)—not as a postulate, but as a result of experience and the development of science, "the homogeneity of the object of physics"—this is what forms the condition for the applicability of measurements and mathematical calculations.

Here is Rey's evaluation of the criterion of practice in the theory of knowledge: "In opposition to the premises of skepticism we have the right to say that the practical value of science flows from its theoretical value" (368)… As for the fact that these premises of skepticism have been adopted by Mach, Poincaré, and their entire school in the most unambiguous manner, Rey prefers to keep silent about it… "Both the one and the other value are two inseparable and strictly parallel aspects of its objective value. To say that a given law of nature has practical value…amounts, in essence, to saying that this law of nature has objective significance… Action upon an object presupposes alteration of the object, a reaction of the object corresponding to our expectations or predictions on the basis of which we undertook this action. Consequently, these expectations or predictions contain elements controlled by the object and our action… In these various theories there is, therefore, a part of the objective" (368). This is entirely and only a materialist theory of knowledge, for other points of view, and Machism in particular, deny the objective, i.e., independent of man and mankind, significance of the criterion of practice.

Conclusion: Rey approached the question from an entirely different angle than Ward, Cohen and Co., but the results obtained by him are the same—acknowledgment of the materialist and idealist tendency as the basis of the division of the two main schools in contemporary physics.

7. Russian "Physicist-Idealist"

N. I. Shishkin "had no preconceived dogmatism at all. He was a convinced advocate of the mechanical explanation of natural phenomena, but for him it was merely a method of investigation" (341)… Hm…hm… Familiar strains!.. "He did not at all think that mechanical theory reveals the very essence of the studied phenomena; he saw in it only the most convenient and fruitful way to unify and ground them for the purposes of science. Therefore for him mechanical understanding of nature and materialist view of it are far from coinciding with one another…". Exactly as with the authors of the "Essays on the Philosophy of Marxism"!.. "On the contrary, it seemed to him that on questions of a higher order, mechanical theory should occupy a strictly critical, even conciliatory position…".

In the language of Machists this is called "transcending the antiquated, narrow and one-sided" opposition of materialism to idealism… "Questions about the first principle and final end of things, about the inner nature of our spirit, about free will, about the immortality of the soul, etc., cannot in the actual breadth of their meaning be subject to its competence—precisely because it, as a method of investigation, is confined within the natural limits of its applicability only to facts of physical experience" (342)… The last two lines are unquestionably plagiarized from "Empiriomonism" by A. Bogdanov.

"Light can be regarded," wrote Shishkin in his article: "On Psycho-physical Phenomena from the Standpoint of Mechanical Theory" ("Questions of Philosophy and Psychology," bk. 1, p. 127), "as substance, as motion, as electricity, as sensation."

It is undeniable that Mr. Lopatin quite correctly classified Shishkin among positivists and that this physicist belonged entirely to the Machist school of the new physics. Shishkin wishes to say by his reasoning about light that different ways of regarding light represent different methods of "organizing experience" (in A. Bogdanov's terminology), equally lawful from one or another standpoint, or different "connections of elements" (in E. Mach's terminology), and that in any case the teaching of physicists about light is not a tracing of objective reality. But Shishkin reasons most poorly. "Light can be regarded as substance, as motion…". There is neither substance without motion nor motion without substance in nature. Shishkin's first "opposition" is senseless… "As electricity…". Electricity is motion of substance, consequently Shishkin is wrong here too. The electromagnetic theory of light has proved that light and electricity are forms of motion of one and the same substance (the ether)… "As sensation…". Sensation is the image of moving matter. In no other way than through sensations can we know anything about any forms of substance and any forms of motion; sensations are aroused by the action of moving matter on our sense organs. This is how natural science looks at it. The sensation of red color reflects oscillations of the ether occurring at approximately 450 trillion times per second. The sensation of blue color reflects oscillations of the ether at approximately 620 trillion times per second. The oscillations of the ether exist independently of our sensations of light. Our sensations of light depend on the action of the oscillations of the ether on the human organ of sight. Our sensations reflect objective reality, i.e., that which exists independently of mankind and human sensations. This is how natural science looks at it. Shishkin's reasoning, directed against materialism, is the cheapest sophistry.

8. The Essence and Significance of "Physical" Idealism

We have seen that the question of the epistemological conclusions from the newest physics has been raised and discussed from the most various points of view in English, German, and French literature. There cannot be the slightest doubt that before us lies a certain international current of ideas, independent of any single philosophical system, but flowing from certain general causes lying outside philosophy. The foregoing survey of the data shows unquestionably that Machism is "connected" with the new physics—and at the same time it shows the radically incorrect conception of this connection disseminated by our Machists. Both in philosophy and in physics, the Machists slavishly follow fashion, being unable to give from their own, Marxist, standpoint a general survey of certain currents and to evaluate their place.

A twofold falsity permeates all the rhetoric on the theme that Mach's philosophy is the "philosophy of twentieth-century natural science," "the newest philosophy of the natural sciences," "the newest natural-scientific positivism," etc. (Bogdanov in the preface to "The Analysis of Sensations," p. IV, XII; compare the same in Yushkevich, Valentinov and Co.). First, Machism is connected ideologically only with one school in one branch of contemporary natural science. Second, and this is the main point, it is connected in Machism to this school not by that which distinguishes it from all other tendencies and systems of idealist philosophy, but by that which is common to it with all philosophical idealism generally. Sufficient it is to cast a glance at the entire current of ideas under consideration to remove all shadow of doubt regarding the correctness of this proposition. Take the physicists of this school: the German Mach, the Frenchman Henri Poincaré, the Belgian P. Duhem, the Englishman C. Pearson. There is much in common among them; they have one basis and one direction, as each of them quite rightly acknowledges, but this commonality does not include either the teaching of empirio-criticism generally, nor even Mach's teaching about the "elements of the world" in particular. None of the three latter physicists are even acquainted with either of these teachings. The commonality among them is "only" one: philosophical idealism, toward which they all without exception lean more or less consciously, more or less decisively. Take the philosophers who rely on this school of the new physics, who endeavor to ground and develop it epistemologically, and you will again see German immanentists, students of Mach, French neo-critics and idealists, English spiritualists, the Russian Lopatin, plus the sole empiriomonist A. Bogdanov. The commonality among all of them is only one, namely that they all more or less consciously, more or less decisively, with either a sharp and hasty deviation toward fideism or with personal aversion to it (A. Bogdanov), conduct philosophical idealism.

The fundamental idea of the school of the new physics under consideration is the denial of objective reality given us in sensation and reflected by our theories, or doubt regarding the existence of such a reality. Here this school departs from the dominant, by general acknowledgment, materialism among physicists (inexactly called realism, neo-mechanism, hylokineticism, and not developed by the physicists themselves with any consciousness)—departs as a school of "physical" idealism.

In order to explain this last term, which sounds very strange, it is necessary to recall one episode from the history of recent philosophy and recent natural science. In 1866 L. Feuerbach fell upon Johannes Müller, the famous founder of modern physiology, and classified him "among the physiological idealists" (Werke, X, S. 197). This physiologist's idealism consisted in the fact that, while investigating the significance of the mechanism of our sense organs in their relation to sensations, pointing out, for example, that the sensation of light is obtained through various kinds of action on the eye, he was inclined to draw from this the denial that our sensations are images of objective reality. This tendency of one school of natural scientists toward "physiological idealism," i.e., toward an idealist interpretation of certain results of physiology, Feuerbach grasped with extraordinary acuteness. The "connection" of physiology with philosophical idealism, predominantly of the Kantian sort, was long afterwards exploited by reactionary philosophy. F. A. Lange trumpeted physiology in favor of Kantian idealism and in refutation of materialism, and from among the immanentists (whom A. Bogdanov so incorrectly assigned to a position midway between Mach and Kant), I. Remke specially inveighed in 1882 against the supposed confirmation of Kantianism by physiology[186]. That a number of eminent physiologists leaned toward idealism and Kantianism in those times is beyond dispute, as is equally undisputed that a number of eminent physicists lean toward philosophical idealism in our time. "Physical" idealism, i.e., the idealism of a certain school of physicists at the end of the nineteenth and beginning of the twentieth century, "refutes" materialism no more than, and is no more convincing in proving the connection of idealism (or empirio-criticism) with natural science, than were the corresponding efforts of F. A. Lange and the "physiological" idealists. The deviation toward reactionary philosophy revealed in both cases by one school of natural scientists in one branch of natural science is a temporary zigzag, a transient sickly period in the history of science, a growing pain caused above all by the sharp upheaval of old established concepts. The connection of contemporary "physical" idealism with the crisis in contemporary physics is universally acknowledged, as we have already indicated. "The arguments of skeptical criticism directed against contemporary physics," writes A. Rey, having in mind not so much skeptics as direct supporters of fideism, like Brunetière,—"reduce, in essence, to the famous argument of all skeptics: to disagreement of opinions" (among physicists). But these disagreements "prove nothing against the objectivity of physics." "In the history of physics, as in all history, one can distinguish large periods characterized by a different form, a different general appearance of theories… As soon as one of those discoveries occurs which resonates through all parts of physics, establishing some cardinal fact previously unknown or incompletely evaluated, the whole appearance of physics changes; a new period begins. So it was after Newton's discoveries, after the discoveries of Joule—Mayer and Carnot—Clausius. The same thing is apparently happening after the discovery of radioactivity… The historian who subsequently observes events from a necessary distance will easily see the constancy of evolution where contemporaries see only conflicts, contradictions, a split into different schools. Apparently, the very crisis which physics experienced in these recent years belongs to the same category (contrary to the conclusions drawn on the basis of this crisis by philosophical criticism). It is a typical crisis of growth (crise de croissance), caused by great new discoveries. It is unquestionable that the crisis leads to a transformation of physics—without this there would be neither evolution nor progress—but it will not change the scientific spirit" (l. c., p. 370–372).

The conciliator Rey endeavors to unite all schools of contemporary physics against fideism! This is well-intentioned falsity, but falsity nonetheless, because the deviation of the Mach—Poincaré—Pearson school toward idealism (i.e., refined fideism) is incontestable. And that objectivity of physics which is connected with the foundations of "scientific spirit," in distinction from fideistic spirit, and which Rey defends so ardently, is nothing other than a "shamefaced" formulation of materialism. The materialist fundamental spirit of physics, like that of all contemporary natural science, will overcome all and every crisis, but only with the indispensable replacement of metaphysical materialism with dialectical materialism.

That the crisis of contemporary physics consists in its retreat from straightforward, decisive, and irrevocable recognition of the objective value of its theories—this the conciliator Rey frequently tries to obscure, but facts are stronger than all conciliatory attempts. "Mathematicians," writes Rey, "accustomed to dealing with a science in which the object—at least apparently—is created by the scholar's mind or in which, in any case, concrete phenomena do not interfere with the investigation, have formed too abstract a conception of physics: in endeavoring to bring it closer to mathematics, they transferred the general theory of mathematics to physics… All experimenters point to the invasion (invasion) of the spirit of mathematics into the methods of physical judgments and into the understanding of physics. Is it not by this influence—which loses nothing of its force from being sometimes hidden—that is often explained the uncertainty, the wavering of thought regarding the objectivity of physics, the roundabout paths by which objectivity is reached, the obstacles that are overcome in the process?..." (227).

This is excellently said. "Wavering of thought" on the question of the objectivity of physics—therein lies the essence of the fashionable "physical" idealism.

"…Abstract fictions of mathematics created, as it were, a certain screen between physical reality and the way mathematicians understand science about this reality. They vaguely feel the objectivity of physics… they wish to be, above all, objective when they undertake physics, they strive to rely on reality and retain this support, but old habits prevail. And, down to energetics, which wished to build the world more firmly and with fewer hypotheses than the old mechanical physics,—which aimed to trace (décalquer) the sensible world rather than recreate it—we still have to do with theories of mathematicians… Mathematicians did everything to save the objectivity of physics, for without objectivity—they understand this very well—there can be no talk of physics… But the complexity of their theories, their roundabout paths leave a feeling of awkwardness. It is too artificial, too refined, too constructed (édifié); the experimenter does not find here that instinctive confidence which the constant contact with physical reality inspires in him… This is what all those physicists say, in essence, who are first and foremost physicists—and their name is legion—or who are only physicists; this is what the whole neo-mechanist school says… The crisis of physics consists in the conquest of physics by the spirit of mathematics. The progress of physics, on one side, and the progress of mathematics, on the other, led in the nineteenth century to a close rapprochement of these two sciences… Theoretical physics became mathematical physics… Then began the period of formal physics, i.e., mathematical physics that had become purely mathematical,—mathematical physics not as a branch of physics but as a branch of mathematics. In this new phase the mathematician, accustomed to conceptual (purely logical) elements constituting the only material of his work, and feeling himself constrained by the crude, material elements which he found insufficiently tractable, could not but strive to abstract from them as much as possible, to conceive them wholly immaterially, purely logically, or even to ignore them altogether. The elements, as real, objective data, i.e., as physical elements, disappeared entirely. Only formal relations remained, represented by differential equations… If the mathematician does not allow himself to be fooled by this constructive work of his mind…, then he will be able to find the connection of theoretical physics with experience, but at first glance, and for the unprepared man, it appears, seemingly, an arbitrary construction of theory… The concept, the pure notion, replaces the real elements… Thus is explained historically, by virtue of the mathematical form adopted by theoretical physics…, the malaise (le malaise), the crisis of physics and its apparent removal from objective facts" (228–232).

Such is the first cause of "physical" idealism. Reactionary encroachments are engendered by the very progress of science. The great success of natural science, the approach to such uniform and simple elements of matter whose laws of motion admit of mathematical treatment, engenders forgetfulness of matter on the part of mathematicians. "Matter disappears," only equations remain. At a new stage of development, and, supposedly, anew, we get the old Kantian idea: Reason prescribes laws to nature. Hermann Cohen, who, as we have seen, rejoices in the idealist spirit of the new physics, goes so far as to preach the introduction of higher mathematics into schools—for the sake of implanting in schoolboys the spirit of idealism driven out by our materialist epoch (Geschichte des Materialismus von A. Lange, 5. Auflage, 1896, Bd. II, S. XLIX[187]). Of course, this is the foolish fancy of a reactionary, and in reality nothing but fleeting enthusiasm for idealism on the part of a small number of specialists can result and can exist. But it is highly characteristic how the drowning man grasps at a straw, what refined means the representatives of educated bourgeoisie attempt to artificially preserve or find a place for fideism, which is engendered in the depths of the masses by ignorance, stupor, and the absurd barbarism of capitalist contradictions.

The other cause that has engendered "physical" idealism is the principle of relativism, the relativity of our knowledge, a principle which is imposed upon physicists with particular force in the period of sharp upheaval of old theories and which—in ignorance of dialectics—inevitably leads to idealism.

This question of the relationship between relativism and dialectics is perhaps the most important in explaining the theoretical misfortunes of Machism. For instance, Rey, like all European positivists, has not the faintest notion of Marxist dialectics. The word dialectics he uses exclusively in the sense of idealist philosophical speculation. Therefore, feeling that the new physics has veered toward relativism, he flounders helplessly, trying to distinguish between moderate and immoderate relativism. Of course, "immoderate relativism logically, if not in practice, borders on true skepticism" (215), but in Poincaré, you see, there is no such "immoderate" relativism. Imagine being able to weigh out a bit more—a bit less relativism, as in an apothecary's scale, and thus set things right with Machism!

In reality, the only theoretically correct formulation of the question of relativism is given by the materialist dialectics of Marx and Engels, and ignorance of it must inevitably lead from relativism to philosophical idealism. Failure to understand this fact alone is, between the way, sufficient to deprive of all significance the absurd little book of Mr. Berman on "Dialectics in the Light of Contemporary Theory of Knowledge": Mr. Berman repeated the old-old nonsense about dialectics which he completely failed to understand. We have already seen that the same failure of understanding is revealed at every step in the theory of knowledge by all the Machists.

All the old truths of physics, down to those considered indisputable and unshakeable, turn out to be relative truths,—consequently, there can be no objective truth independent of mankind. So reasons not only all of Machism, but all "physical" idealism generally. That from the sum of relative truths in their development there is formed an absolute truth,—that relative truths represent relatively true reflections of an object independent of mankind,—that these reflections become ever more true,—that in each scientific truth, despite its relativity, there is an element of absolute truth,—all these propositions, self-evident to anyone who has thought over Engels' "Anti-Dühring," constitute a book sealed with seven seals for "contemporary" theory of knowledge.

Such works as "The Theory of Physics" by P. Duhem[188] or "The Concepts and Theories of Modern Physics" by Stalloitalics[189], which Mach especially recommends, show with extraordinary vividness that these "physical" idealists attach the greatest significance precisely to demonstrating the relativity of our knowledge, wavering, in essence, between idealism and dialectical materialism. Both authors, belonging to different epochs and approaching the question from different standpoints (Duhem—a physicist by specialty, having worked twenty years in this field; Stallo—a former true Hegelian, ashamed of the natural philosophy he had issued in 1848 in the old Hegelian spirit), struggle most energetically against the atomistic-mechanical understanding of nature. They prove the limitations of such an understanding, the impossibility of recognizing it as the limit of our knowledge, the ossification of many concepts in writers adhering to this understanding. And such a shortcoming of old materialism is unquestionable; lack of understanding of the relativity of all scientific theories, ignorance of dialectics, exaggeration of the mechanical standpoint—for this Engels reproached former materialists. But Engels succeeded (unlike Stallo) in throwing out Hegelian idealism and in understanding with genius the true kernel of Hegelian dialectics. Engels renounced old, metaphysical materialism in favor of dialectical materialism, not in favor of relativism sliding into subjectivism. "Mechanical theory," says, for instance, Stallo, "together with all metaphysical theories hypostasizes particular, ideal, and perhaps purely conventional groups of attributes or individual attributes and treats them as different kinds of objective reality" (p. 150). This is true if you do not renounce the recognition of objective reality and if you struggle against metaphysics as anti-dialectical. Stallo does not give himself a clear account of this. He did not understand materialist dialectics and therefore often slides through relativism into subjectivism and idealism.

The same with Duhem. With tremendous expenditure of labor, with a series of examples from the history of physics as interesting and valuable as those often met with in Mach, he proves that "every law of physics is temporary and relative because it is approximate" (280). And the man pushes against an open door! thinks the Marxist, reading long arguments on this theme. But therein lies the misfortune of Duhem, Stallo, Mach, Poincaré—that they do not see the door opened by dialectical materialism. Unable to give a correct formulation of relativism, they slide from it into idealism. "A law of physics, properly speaking, is neither true nor false, but approximate," writes Duhem (p. 274). In this "but" there already begins falsity, the beginning of erasing the boundary between a theory of science approximately reflecting an object, i.e., approaching objective truth, and a theory that is arbitrary, fantastic, purely conventional, such as the theory of religion or the theory of chess.

This falsity reaches in Duhem the point of declaring the question of whether "material reality" corresponds to sensible phenomena a metaphysical one (p. 10): away with the question of reality; our concepts and hypotheses are simple symbols (signes, p. 26), "arbitrary" (27) constructions, etc. From here it is one step to idealism, to the "physics of the believer," which Mr. Peter Duhem in the spirit of Kantianism preaches (in Rey, p. 162; cf. p. 160). And the good-natured Adler (Fritz)—also a Machist desiring to be a Marxist!—found nothing wiser than to "correct" Duhem as follows: he, supposedly, eliminates "realities hidden behind phenomena, only as objects of theory, not as objects of reality"[190]. This is already the familiar to us criticism of Kantianism from the standpoint of Hume and Berkeley.

But there can be no question of any conscious Kantianism on P. Dühring's part. He simply wavers, like Mach, not knowing what to rely upon for his relativism. In a whole series of passages he comes very close to dialectical materialism. We know sound "as it exists in relation to us, and not such as it is in itself, in the bodies that produce sound. This reality, from which our sensations reveal only the external and superficial, theoretical acoustics gives us the possibility of knowing. They tell us that where our perceptions grasp only that semblance which we call sound, there actually exists a periodic, miniature, very rapid motion," and so on (p. 7). Not bodies are symbols of sensations, but sensations are symbols (or more accurately, images) of bodies. "The development of physics causes a constant struggle between nature, which does not tire of giving material, and Reason, which does not tire of knowing" (p. 32) – nature is infinite, just as the tiniest particle of it is infinite (the electron included), but Reason just as infinitely transforms "things-in-themselves" into "things-for-us." "The struggle between reality and the laws of physics will last infinitely; to every law that physics formulates, reality will oppose, sooner or later, crude refutation – refutation by means of fact; but physics will tirelessly retouch, modify, complicate the refuted law" (290). This would be a perfectly correct exposition of dialectical materialism, if only the author firmly held fast to the existence, independent of mankind, of this objective reality. "… The theory of physics is not a purely artificial system, convenient today – useless tomorrow; it is a classification ever more and more natural, a reflection ever more and more clear of those realities which the experimental method cannot contemplate immediately" (literally: face to face: *face à face*, p. 445).

The Machist Dühring with this last phrase flirts with Kantian idealism: as though a path is opening up for another method, besides the "experimental"; as though we do not know directly, immediately, face to face the "things-in-themselves." But if the theory of physics becomes ever more and more natural, then, that means, independent of our consciousness there exists a "nature," a reality, "reflected" by this theory – precisely such is the view of dialectical materialism.

In a word, today's "physical" idealism, just as yesterday's "physiological" idealism, means only that one school of natural scientists in one branch of natural science has slid into reactionary philosophy, being unable to rise directly and at once from metaphysical materialism to dialectical materialism[191]. This step contemporary physics makes and will make, but it moves toward the only correct method and the only correct philosophy of natural science not directly, but in zigzags, not consciously, but spontaneously, not seeing clearly its "ultimate goal," but approaching it gropingly, wavering, sometimes even backward. Contemporary physics is in labor. It is giving birth to dialectical materialism. The labor pains are severe. Besides the living and viable organism, they inevitably produce some dead products, some refuse, destined for removal to a place for filth. To the number of these refuse belongs all physical idealism, all empirio-critical philosophy together with empirio-symbolism, empirio-monism, and so on and so forth.